Marine Department Promotes Koh Man Nai's Unique Sea Parting
The Marine Department is promoting Koh Man Nai in Rayong as a hidden paradise featuring the longest sea‑parting sandbar in the Eastern Gulf. Visitors can explore the island’s turtle conservation centre, rare migratory bird habitat, and vibrant coral reefs suitable for snorkeling and diving. The best time to visit is from October to May, especially February to April when seas are calm and clear.
The Marine Department invites tourists to discover a hidden paradise at sea! Koh Man Nai, the only 'sea parting' wonder in the Eastern Gulf, offers visitors a chance to check in and visit sea turtles and a rare migratory bird sanctuary. Dated 14 October 2026, the Marine Resources and Coastal Management Department promotes Koh Man Nai as the largest and closest island to shore among the Man Island group (Koh Man Nai, Koh Man Klang, Koh Man Nok), located in Kram Subdistrict, Klaeng District, Rayong Province, covering about 131 rai of pristine natural area. It is more than a typical tourist island; it is a gem of the Eastern Gulf coast. The highlight is the ‘sea parting’ or ‘dragon’s spine’ — a sandbar about 600–700 meters long that emerges at low tide, curving like a dragon’s back across clear water, the longest such phenomenon in the eastern Gulf, most visible from May onward. Walking on the soft sand lets tourists enjoy 360‑degree sea breezes and perfect photo opportunities.
The island also hosts a sea‑turtle conservation centre established in 1979 under the royal initiative of Her Majesty Queen Sirikit, where hatchlings are raised and breeding pairs of various species, such as the green and hawksbill turtles, are cared for. The centre runs educational exhibits and participates in the rehabilitation and protection of the protected horse‑conch mollusk found around the coral reefs.
Koh Man Nai is an important snorkeling and diving spot for Rayong, with beautiful natural coral reefs and successful artificial reef projects that now support colorful fish populations. Visitors can also join turtle‑rehabilitation programs run with local community networks.
Access is via tourist boats from the Makham Pom Pier or the Pranang River Pier, with options to join organized tours or travel independently. Activities available on the island include ecotourism, snorkeling, scuba diving, bird watching, turtle watching, fishing, and squid fishing.
The ideal time to visit is from October to May each year, especially February to April when winds are calm, there is no monsoon, and the water is clearest. During the monsoon season, waves become strong and the water turns turbid, prompting operators to suspend services for safety.
